The Star Trek: The Next Generation episode "Chain of Command, Part II" showed Captain Jean-Luc Picard captured and tortured by the Cardassians. The Cardassian officer Madred tried to break Picard's mind. He offered Picard a life of imprisoned comfort, if only he would say that there were five lights in the room, not four.

But Picard needed not five to boogie. There were four disco balls above the dance floor.

The clip embedded below leaves out the disco references, but you'll see them in the full episode.